Mechanism of EBV inducing anti-tumour immunity and its therapeutic use.

Tumour-associated antigens (TAAs) comprise a large set of non-mutated cellular antigens recognized by T cells in human and murine cancers. Their potential as targets for immunotherapy has been explored for more than two decades1, yet the origins of TAA-specific T cells remain unclear. While tumour cells may be an important source of TAAs for T cell priming2, several recent studies suggest that infection with some viruses, including Epstein-Barr virus and influenza virus can elicit T cell responses against abnormally expressed cellular antigens that function as TAAs3,4. However, the cellular and molecular basis of such responses remains undefined. Here we show that expression of the Epstein-Barr virus signalling protein LMP1 in B cells provokes T cell responses to multiple TAAs. LMP1 signalling leads to overexpression of many cellular antigens previously shown to be TAAs, their presentation on major histocompatibility complex classes I (MHC-I) and II (MHC-II) (mainly through the endogenous pathway) and the upregulation of costimulatory ligands CD70 and OX40L, thereby inducing potent cytotoxic CD4+ and CD8+ T cell responses. These findings delineate a mechanism of infection-induced anti-tumour immunity. Furthermore, by ectopically expressing LMP1 in tumour B cells from patients with cancer and thereby enabling them to prime T cells, we develop a general approach for rapid production of autologous cytotoxic CD4+ T cells against a wide range of endogenous tumour antigens, such as TAAs and neoantigens, for treating B cell malignancies. This work stresses the need to revisit classical concepts concerning viral and tumour immunity, which will be critical to fully understand the impact of common infections on human health and to improve the rational design of immune approaches to treatment of cancers.

Mass Spectrometry Profiling of HLA-Associated Peptidomes in Mono-allelic Cells Enables More Accurate Epitope Prediction.

Identification of human leukocyte antigen (HLA)-bound peptides by liquid chromatography-tandem mass spectrometry (LC-MS/MS) is poised to provide a deep understanding of rules underlying antigen presentation. However, a key obstacle is the ambiguity that arises from the co-expression of multiple HLA alleles. Here, we have implemented a scalable mono-allelic strategy for profiling the HLA peptidome. By using cell lines expressing a single HLA allele, optimizing immunopurifications, and developing an application-specific spectral search algorithm, we identified thousands of peptides bound to 16 different HLA class I alleles. These data enabled the discovery of subdominant binding motifs and an integrative analysis quantifying the contribution of factors critical to epitope presentation, such as protein cleavage and gene expression. We trained neural-network prediction algorithms with our large dataset (>24,000 peptides) and outperformed algorithms trained on datasets of peptides with measured affinities. We thus demonstrate a strategy for systematically learning the rules of endogenous antigen presentation.

Neoantigen vaccine generates intratumoral T cell responses in phase Ib glioblastoma trial.

Neoantigens, which are derived from tumour-specific protein-coding mutations, are exempt from central tolerance, can generate robust immune responses1,2 and can function as bona fide antigens that facilitate tumour rejection3. Here we demonstrate that a strategy that uses multi-epitope, personalized neoantigen vaccination, which has previously been tested in patients with high-risk melanoma4-6, is feasible for tumours such as glioblastoma, which typically have a relatively low mutation load1,7 and an immunologically 'cold' tumour microenvironment8. We used personalized neoantigen-targeting vaccines to immunize patients newly diagnosed with glioblastoma following surgical resection and conventional radiotherapy in a phase I/Ib study. Patients who did not receive dexamethasone-a highly potent corticosteroid that is frequently prescribed to treat cerebral oedema in patients with glioblastoma-generated circulating polyfunctional neoantigen-specific CD4+ and CD8+ T cell responses that were enriched in a memory phenotype and showed an increase in the number of tumour-infiltrating T cells. Using single-cell T cell receptor analysis, we provide evidence that neoantigen-specific T cells from the peripheral blood can migrate into an intracranial glioblastoma tumour. Neoantigen-targeting vaccines thus have the potential to favourably alter the immune milieu of glioblastoma.

Corrigendum: An immunogenic personal neoantigen vaccine for patients with melanoma.

This corrects the article DOI: 10.1038/nature22991.

Impact of allele-specific anti-human leukocyte antigen class I antibodies on organ allocation.

Technological advances in the field of histocompatibility have allowed us to define anti-human leukocyte antigen (HLA) antibody specificity at the allelic level. However, how allele-specific antibodies affect organ allocation is poorly studied. We examined allelic specificities of class I HLA antibodies in 6726 consecutive serum samples from 2953 transplant candidates and evaluated their impact on the corresponding crossmatch and organ allocation. Out of 17 class I HLA antigens represented by >1 allele in the LABScreen single antigen bead assay, 12 had potential allele-specific reactivity. Taking advantage of our unbiased cohort of deceased donor-candidate testing (123,135 complement-dependent cytotoxicity crossmatches between 2014 and 2017), we estimated that the presence of allele-specific antibody detected using a single antigen bead assay (median fluorescence intensity, >3000) against only the rare allele was a poor predictor of a positive complement-dependent cytotoxicity crossmatch, with a positive predictive value of 0% to 7%, compared with 52.5% in allele-concordant class I HLA antibodies against A or B locus antigens. Further, we confirmed allele-specific reactivity using flow crossmatch in 3 scenarios: A11:01/A11:02, A68:01/A68:02, and B44:02/B44:03. Our results suggest that allele-specific antibodies may unnecessarily exclude transplant candidates (up to 10%) from organ offers by overcalling unacceptable antigens; incorporation of selective reactivity pattern in allocation may promote precision matching and more equitable allocation.

An immunogenic personal neoantigen vaccine for patients with melanoma.

Effective anti-tumour immunity in humans has been associated with the presence of T cells directed at cancer neoantigens, a class of HLA-bound peptides that arise from tumour-specific mutations. They are highly immunogenic because they are not present in normal tissues and hence bypass central thymic tolerance. Although neoantigens were long-envisioned as optimal targets for an anti-tumour immune response, their systematic discovery and evaluation only became feasible with the recent availability of massively parallel sequencing for detection of all coding mutations within tumours, and of machine learning approaches to reliably predict those mutated peptides with high-affinity binding of autologous human leukocyte antigen (HLA) molecules. We hypothesized that vaccination with neoantigens can both expand pre-existing neoantigen-specific T-cell populations and induce a broader repertoire of new T-cell specificities in cancer patients, tipping the intra-tumoural balance in favour of enhanced tumour control. Here we demonstrate the feasibility, safety, and immunogenicity of a vaccine that targets up to 20 predicted personal tumour neoantigens. Vaccine-induced polyfunctional CD4+ and CD8+ T cells targeted 58 (60%) and 15 (16%) of the 97 unique neoantigens used across patients, respectively. These T cells discriminated mutated from wild-type antigens, and in some cases directly recognized autologous tumour. Of six vaccinated patients, four had no recurrence at 25 months after vaccination, while two with recurrent disease were subsequently treated with anti-PD-1 (anti-programmed cell death-1) therapy and experienced complete tumour regression, with expansion of the repertoire of neoantigen-specific T cells. These data provide a strong rationale for further development of this approach, alone and in combination with checkpoint blockade or other immunotherapies.

Density functional theory investigation of mechanisms of degradation reactions of sulfonated PEEK membranes with OH radicals in fuel cells: addition-elimination reactions and acid catalyzed water elimination.

Sulfonated polyether (ether) ketone or sulfonated PEEK (sPEEK) membranes are one possible candidate for proton-transfer membranes in hydrogen fuel cells. Reaction with hydroxy radicals is expected to be a significant source of degradation of these membranes during fuel cell operation. In this work, the reactivity of the sPEEK polymer molecule with OH radicals is studied by M062X hybrid density functional calculations of the energetics of several reaction paths in a water environment as modeled by polarized continuum model calculations. Reactants, products, encounter minima and transition states are optimized for a reaction pathway in which OH addition is followed by acid-catalyzed water elimination which cationizes the polymer, degradation is expected to follow this reaction as the unstable cation then undergoes bond-breaking or other reactions. Two pathways for this acid-catalyzed cationization, one in which a water molecule plays the role of an additional co-catalyst, are reported. Further calculations explore reaction pathways in which addition of OH to the polymer is followed by bond breaking reactions which would break the polymer chain or the bond between the polymer and sulfonyl groups. Examination of the free energy barriers to all these reactions, relative to reactants, suggests that these direct bond-breaking reactions may compete somewhat with acid-catalyzed water elimination following OH addition. Supplementary Information: The online version contains supplementary material available at 10.1007/s00214-023-02981-2.

Evaluation and clinical impact of a pharmacist-led, interdisciplinary service focusing on education, monitoring and toxicity management of immune checkpoint inhibitors.

INTRODUCTION: Immune-related adverse events are complications of immune checkpoint inhibitors which require robust patient education and proactive follow-up to ensure timely identification and management. Oncology pharmacist practice models with other anticancer modalities have been well documented, but there is limited evidence assessing the spectrum of pharmacist interventions in patients receiving immune checkpoint inhibitor(s) and the impact of these interventions on patient outcomes. METHODS: Patients initiated on immune checkpoint inhibitor(s) from 1 January 2016 to 31 August 2019 were included for data collection and analysis. Part 1 featured an intensive pharmacist follow-up cohort (study cohort) and summarized pharmacist interventions. Part 2 compared patient outcomes between the study cohort and a standard of care cohort (control cohort) from a different oncology centre. Patient outcomes included emergency department visits not resulting in admission, hospitalizations due to immune-related adverse event(s), immune checkpoint inhibitor cycles received, treatment discontinuation due to immune-related adverse event(s), completion of finite programmed death-1/death-1 ligand treatment course and completion of ipilimumab. Clinical outcomes were compared using a retrospective, matched cohort design based on age, cancer diagnosis and immune checkpoint inhibitor(s). RESULTS: A total of 143 patients were included in Part 1 encompassing 1664 pharmacist recommendations across 11 categories. The matched cohort yielded 92 matches (n = 184) with a higher odds of immune checkpoint inhibitor discontinuation due to immune-related adverse event(s) in the control cohort (odds ratio (OR) (95% confidence interval (CI)) = 5.5 (1.2-24.8); p = 0.022). CONCLUSION: Intensive immune-related adverse event education, proactive follow-up and immune-related adverse event management by pharmacists result in clinically meaningful interventions which correlate to improved patient outcomes, namely lower odds of treatment discontinuation due to immune-related adverse event(s).

Ectopic extramammary Paget disease in thoracic location.

Extramammary Paget disease (EMPD) is a rare skin cancer that affects areas with a high concentration of apocrine glands including genital, axillary, and anal skin. When it affects other locations it is called ectopic extramammary Paget disease (E-EMPD) and is uncommon. To date, there are only 45 case reports to the best of our knowledge. The clinical manifestation is typically a soft, red or bright pink patch or plaque with scattered white islands of hyperkeratosis and erosion. Diagnostic confirmation requires conventional histology with immunohistochemistry. The importance of immunohistochemical staining for the diagnosis of primary neoplasia, without underlying malignancy, is highlighted. We report the first Latin American confirmed case, to our knowledge, of primary E-EMPD in a 55-year-old man with a 1-year history of asymptomatic thoracic plaque.

A cloning and expression system to probe T-cell receptor specificity and assess functional avidity to neoantigens.

Recent studies have highlighted the promise of targeting tumor neoantigens to generate potent antitumor immune responses and provide strong motivation for improving our understanding of antigen-T-cell receptor (TCR) interactions. Advances in single-cell sequencing technologies have opened the door for detailed investigation of the TCR repertoire, providing paired information from TCRα and TCRß, which together determine specificity. However, a need remains for efficient methods to assess the specificity of discovered TCRs. We developed a streamlined approach for matching TCR sequences with cognate antigen through on-demand cloning and expression of TCRs and screening against candidate antigens. Here, we first demonstrate the system's capacity to identify viral-antigen-specific TCRs and compare the functional avidity of TCRs specific for a given antigen target. We then apply this system to identify neoantigen-specific TCR sequences from patients with melanoma treated with personalized neoantigen vaccines and characterize functional avidity of neoantigen-specific TCRs. Furthermore, we use a neoantigen-prediction pipeline to show that an insertion-deletion mutation in a putative chronic lymphocytic leukemia (CLL) driver gives rise to an immunogenic neoantigen mut-MGA, and use this approach to identify the mut-MGA-specific TCR sequence. This approach provides a means to identify and express TCRs, and then rapidly assess antigen specificity and functional avidity of a reconstructed TCR, which can be applied for monitoring antigen-specific T-cell responses, and potentially for guiding the design of effective T-cell-based immunotherapies.

Immunity to X-linked inhibitor of apoptosis protein (XIAP) in malignant melanoma and check-point blockade.

Expression of inhibitors of apoptosis protein (IAP) family members is associated with poor prognosis in cancer patients. Immunity to ML-IAP (livin) and survivin has been well studied in patients with a variety of tumors. XIAP, the most potent inhibitor of apoptosis, is widely expressed in melanoma. To better define its potential role as an immunogenic target, cellular and humoral responses to XIAP were investigated in patients with advanced melanoma. An overlapping peptide library covering the full length of the XIAP protein was used to screen T cell responses of peripheral blood mononuclear cells (PBMC) from stage-IV melanoma patients treated with or without anti-CTLA4 (ipilimumab). The screen identified an array of peptides that predominantly induced CD4+ T cell responses. XIAP epitope-specific CD4+ T cells revealed proliferative responses to melanoma cells that express XIAP. Humoral responses to XIAP were also explored. Cellular and humoral responses to XIAP were associated with beneficial clinical outcomes after ipilimumab-based treatment, supporting XIAP as a potential therapeutic target.

ATMIN is a transcriptional regulator of both lung morphogenesis and ciliogenesis.

Initially identified in DNA damage repair, ATM-interactor (ATMIN) further functions as a transcriptional regulator of lung morphogenesis. Here we analyse three mouse mutants, Atmin(gpg6/gpg6), Atmin(H210Q/H210Q) and Dynll1(GT/GT), revealing how ATMIN and its transcriptional target dynein light chain LC8-type 1 (DYNLL1) are required for normal lung morphogenesis and ciliogenesis. Expression screening of ciliogenic genes confirmed Dynll1 to be controlled by ATMIN and further revealed moderately altered expression of known intraflagellar transport (IFT) protein-encoding loci in Atmin mutant embryos. Significantly, Dynll1(GT/GT) embryonic cilia exhibited shortening and bulging, highly similar to the characterised retrograde IFT phenotype of Dync2h1. Depletion of ATMIN or DYNLL1 in cultured cells recapitulated the in vivo ciliogenesis phenotypes and expression of DYNLL1 or the related DYNLL2 rescued the effects of loss of ATMIN, demonstrating that ATMIN primarily promotes ciliogenesis by regulating Dynll1 expression. Furthermore, DYNLL1 as well as DYNLL2 localised to cilia in puncta, consistent with IFT particles, and physically interacted with WDR34, a mammalian homologue of the Chlamydomonas cytoplasmic dynein 2 intermediate chain that also localised to the cilium. This study extends the established Atmin-Dynll1 relationship into a developmental and a ciliary context, uncovering a novel series of interactions between DYNLL1, WDR34 and ATMIN. This identifies potential novel components of cytoplasmic dynein 2 and furthermore provides fresh insights into the molecular pathogenesis of human skeletal ciliopathies.

The transcription factor PPARα is overexpressed and is associated with a favourable prognosis in IDH-wildtype primary glioblastoma.

AIMS: PPARα agonists are in current clinical use as hypolipidaemic agents and show significant antineoplastic effects in human glioblastoma models. To date however, the expression of PPARα in large-scale glioblastoma datasets has not been examined. We aimed to investigate the expression of the transcription factor PPARα in primary glioblastoma, the relationship between PPARα expression and patients' clinicopathological features and other molecular markers associated with gliomagenesis. METHODS AND RESULTS: With protein immunoblotting techniques and reverse transcription quantitative real-time PCR, PPARα was found to be significantly overexpressed in glioblastoma compared with control brain tissue (P = 0.032 and P = 0.005). PPARA gene expression was found to be enriched in the classical glioblastoma subtype within The Cancer Genome Atlas (TCGA) dataset. Although not associated with overall survival when assessed by immunohistochemistry, cross-validation with the TCGA dataset and multivariate analyses identified PPARA gene expression as an independent prognostic marker for overall survival (P = 0.042). Finally, hierarchical clustering revealed novel, significant associations between high PPARA expression and a putative set of glioblastoma molecular mediators including EMX2, AQP4, and NTRK2. CONCLUSIONS: PPARα is overexpressed in primary glioblastoma and high PPARA expression functions as an independent prognostic marker in the glioblastoma TCGA dataset. Further studies are required to explore genetic associations with high PPARA expression and to analyse the predictive role of PPARα expression in glioblastoma models in response to PPARα agonists.

The Use of Transdermal Therapeutic Systems in Psychiatric Care: A Primer on Patches.

BACKGROUND: Numerous currently available medications that act in the central nervous system can be delivered transdermally. Such medications include cholinesterase inhibitors for dementia, methylphenidate (MPH) for attention-deficit hyperactivity disorder, monoamine oxidase inhibitors (MAOIs) for depression, dopamine agonists for Parkinson disease and restless leg syndrome, and clonidine for attention-deficit hyperactivity disorder and impulse-control disorders. OBJECTIVE: This article aims to review the literature related to transdermal delivery systems from the perspective of clinical practice and research related to their use in the treatment of psychiatric conditions. RESULTS: Most of the currently available transdermal systems have psychotropic properties or utility in the behavioral health arena and, therefore, are of clinical relevance to consultation-liaison psychiatrists or practitioners of psychosomatic medicine. We discuss their efficacy and safety profiles. We provide a table of these agents and their uses. CONCLUSIONS: Transdermal delivery (i.e., patches) for medicines with psychotropic properties allows mental health providers to customize therapy for patients by altering the duration of therapy, minimizing first-pass metabolism and the potential for drug-drug interactions, and decreasing the risk for gastrointestinal irritation.

Strategies for the prescription of psychotropic drugs with black box warnings.

BACKGROUND: The Black Box Warning (BBW) is the Food and Drug Administration's highest level of drug warning. It signifies that a medication has serious (or potentially life-threatening) side effects and is prominently displayed on a medication's package insert. It literally consists of the medication warning and is surrounded by a bold black border. OBJECTIVE: This article aims to review data related to BBWs on psychotropic medications currently used in clinical practice, with special attention to clinical situations and questions relevant to consultation-liaison psychiatrists. RESULTS: We review 3 clinical advisories or BBWs for psychotropic medications (i.e., antidepressant medication and suicidality in the pediatric population, stimulant medication and sudden death in the pediatric population, and antipsychotic medication and increased mortality in the elderly) and discuss the effect they have had on prescribing practices. We provide a table of current BBWs relevant to psychotropic medications. CONCLUSIONS: BBWs can have unintended and far-reaching consequences, albeit with a limited ability to target specific populations and practice patterns. Although it is critical for clinicians to be aware of these serious potential side effects and to inform patients about these warnings, medications with boxed warnings remain Food and Drug Administration-approved and may have critically important therapeutic roles.

Foxj1 regulates floor plate cilia architecture and modifies the response of cells to sonic hedgehog signalling.

Sonic hedgehog signalling is essential for the embryonic development of many tissues including the central nervous system, where it controls the pattern of cellular differentiation. A genome-wide screen of neural progenitor cells to evaluate the Shh signalling-regulated transcriptome identified the forkhead transcription factor Foxj1. In both chick and mouse Foxj1 is expressed in the ventral midline of the neural tube in cells that make up the floor plate. Consistent with the role of Foxj1 in the formation of long motile cilia, floor plate cells produce cilia that are longer than the primary cilia found elsewhere in the neural tube, and forced expression of Foxj1 in neuroepithelial cells is sufficient to increase cilia length. In addition, the expression of Foxj1 in the neural tube and in an Shh-responsive cell line attenuates intracellular signalling by decreasing the activity of Gli proteins, the transcriptional mediators of Shh signalling. We show that this function of Foxj1 depends on cilia. Nevertheless, floor plate identity and ciliogenesis are unaffected in mouse embryos lacking Foxj1 and we provide evidence that additional transcription factors expressed in the floor plate share overlapping functions with Foxj1. Together, these findings identify a novel mechanism that modifies the cellular response to Shh signalling and reveal morphological and functional features of the amniote floor plate that distinguish these cells from the rest of the neuroepithelium.

Older Adults' Use of and Interest in Technology and Applications for Health Management: A Survey Study.

Background: Older adults face challenges with managing their medications, obtaining health education, and accessing health services. Mobile health (mHealth), defined as any medical or public health practice facilitated through mobile devices, could help to overcome these difficulties. Objectives: To determine what technologies and apps are in current use by older adults, to explore the types of technologies and apps that may be of interest to people in this age group, to explore concerns about technologies, and to examine any age-related differences. Methods: Adults 60 years of age or older were invited to complete a 35-item electronic survey, in either French or English, which was distributed through social media and by email from organizations working with older adults. The survey was conducted in mid-2020. Results: A total of 266 respondents completed some or all of the survey. Most participants had a mobile phone (229/243, 94.2%), and approximately one-third (78/222, 35.1%) had used a health-related app in the previous 12 months; this level of usage was consistent across age groups. Most respondents were interested in using an app to improve their health (171/225, 76.0%), with variation by age: highest among those 60-64 years of age (82/95, 86.3%), lower among those 80 years or older (40/52, 76.9%), and lowest among those 65-69 years of age (6/14, 42.9%). Most older adults were interested in using an app to ask questions of pharmacists (161/219, 73.5%) and to review their medications (154/218, 70.6%). Participants' mHealth concerns focused on costs, disclosure of personal information, effectiveness, usability, and endorsement by health care providers. The study limitations included challenges related to electronic recruitment and survey distribution, as well as a high representation of participants with postsecondary education. Conclusions: These findings suggest that a substantial proportion of older adults are already using and are interested in using mHealth for health information, to ask questions, and/or to review their medications with a health care team member.

Contexte: Les personnes âgées sont confrontées à des difficultés pour gérer leurs médicaments, s'informer sur la santé et accéder aux services de santé. Les applications de « santé mobile ¼, définies comme toute pratique médicale ou de santé publique facilitée par des appareils mobiles, pourraient aider à surmonter ces difficultés. Objectifs: Déterminer quelles technologies et applications sont actuellement utilisées par les aînés; examiner celles qui pourraient être intéressantes dans cette tranche d'âge; étudier les préoccupations concernant les technologies et examiner les différences liées à l'âge. Méthodes: Des adultes d'au moins 60 ans ont été invités à répondre à un sondage électronique comprenant 35 questions en français ou en anglais. Ce sondage, mené à la mi-2020, a été diffusé par des organismes travaillant avec des aînés via les médias sociaux et par courriel. Résultats: Au total, 266 participants y ont répondu en partie ou en totalité. La plupart des répondants avaient un téléphone portable (229/243, 94,2 %) et environ un tiers (78/222, 35,1 %) avaient utilisé une application liée à la santé au cours des 12 derniers mois; ce taux d'utilisation était constant tous groupes d'âge confondus. La plupart des répondants souhaitaient utiliser une application pour améliorer leur santé (171/225, 76,0 %), avec des variations du taux d'utilisation selon l'âge : le plus élevé chez les 60 à 64 ans (82/95, 86,3 %), un peu moins chez les 80 ans ou plus (40/52, 76,9 %), et le plus bas chez les 65 à 69 ans (6/14, 42,9 %). La plupart des personnes âgées souhaitent utiliser une application pour poser des questions aux pharmaciens (161/219, 73,5 %) et pour s'informer sur leurs médicaments (154/218, 70,6 %). Les préoccupations des participants en matière de « santé mobile ¼ portaient sur les coûts, la divulgation d'informations personnelles, l'efficacité, la convivialité et l'approbation par les prestataires de soins de santé. On notera, parmi les limites de l'étude, les défis liés au recrutement électronique et à la distribution électronique des sondages, ainsi qu'une forte représentation de participants ayant fait des études postsecondaires. Conclusions: Ces résultats portent à croire qu'une proportion importante d'adultes âgés utilisent déjà la technologie de « santé mobile ¼ et souhaitent l'utiliser pour obtenir des informations sur la santé, poser des questions et/ou s'informer sur leurs médicaments auprès d'un membre de l'équipe de soins de santé.

Density functional theory investigation of mechanisms of degradation reactions of sulfonated PEEK membranes with OH radicals in fuel cells: Addition-elimination reactions and acid catalyzed water elimination.

Sulfonated polyether (ether) ketone, or sulfonated PEEK (sPEEK) membranes are one possible candidate for proton-transfer membranes in hydrogen fuel cells. Reaction with hydroxy radicals is expected to be a significant source of degradation of these membranes during fuel cell operation. In this work, the reactivity of the sPEEK polymer molecule with OH radicals is studied by M062X hybrid density functional calculations of the energetics of several reaction paths in a water environment as modeled by polarized continuum model (PCM) calculations. Reactants, products, encounter minima and transition states are optimized for a reaction pathway in which OH addition is followed by acid-catalyzed water elimination which cationizes the polymer, degradation is expected to follow this reaction as the unstable cation then undergoes bond-breaking or other reactions. Two pathways for this acid-catalyzed cationization, one in which a water molecule plays the role of an additional co-catalyst, are reported. Further calculations explore reaction pathways in which addition of OH to the polymer is followed by bond breaking reactions which would break the polymer chain or the bond between the polymer and sulfonyl groups. Examination of the free energy barriers to all these reactions, relative to reactants, suggest that these direct bond-breaking reactions may compete somewhat with acid-catalyzed water elimination following OH addition.

Detection and annotation of transposable element insertions and deletions on the human genome using nanopore sequencing.

Repetitive sequences represent about 45% of the human genome. Some are transposable elements (TEs) with the ability to change their position in the genome, creating genetic variability both as insertions or deletions, with potential pathogenic consequences. We used long-read nanopore sequencing to identify TE variants in the genomes of 24 patients with antithrombin deficiency. We identified 7 344 TE insertions and 3 056 TE deletions, 2 926 were not previously described in publicly available databases. The insertions affected 3 955 genes, with 6 insertions located in exons, 3 929 in introns, and 147 in promoters. Potential functional impact was evaluated with gene annotation and enrichment analysis, which suggested a strong relationship with neuron-related functions and autism. We conclude that this study encourages the generation of a complete map of TEs in the human genome, which will be useful for identifying new TEs involved in genetic disorders.

Integrated Immunopeptidomic and Proteomic Analysis of COVID-19 lung biopsies.

Introduction: Severe respiratory illness is the most prominent manifestation of patients infected with SARS-CoV-2, and yet the molecular mechanisms underlying severe lung disease in COVID-19 affected patients still require elucidation. Human leukocyte antigen class I (HLA-I) expression is crucial for antigen presentation and the host's response to SARS-CoV-2. Methods: To gain insights into the immune response and molecular pathways involved in severe lung disease, we performed immunopeptidomic and proteomic analyses of lung tissues recovered at four COVID-19 autopsy and six non-COVID-19 transplants. Results: We found signals of tissue injury and regeneration in lung fibroblast and alveolar type I/II cells, resulting in the production of highly immunogenic self-antigens within the lungs of COVID-19 patients. We also identified immune activation of the M2c macrophage as the primary source of HLA-I presentation and immunogenicity in this context. Additionally, we identified 28 lung signatures that can serve as early plasma markers for predicting infection and severe COVID-19 disease. These protein signatures were predominantly expressed in macrophages and epithelial cells and were associated with complement and coagulation cascades. Discussion: Our findings emphasize the significant role of macrophage-mediated immunity in the development of severe lung disease in COVID-19 patients.